Is Your Project Timeline Based on a Sample of 1? Do this INSTEAD...
Letโs face it, as human beings weโre terrible at estimating how long a project will take to complete (even Elon Musk has been off by YEARS in his predictions for SpaceX!)
๐ช๐๐ฌ? Two reasons:
โ Weโre simply too optimistic and assume everything will go well.
โ Calculating a single completion time does not FORCE us to consider alternate scenarios.
Once the date been communicated, everyone tends to remember THE DATE โ and not the underlying assumptions behind it - no matter how carefully they're stated.
๐ ๐ฆ๐ผ๐น๐๐๐ถ๐ผ๐ป?
A variation of PERT analysis; PERT stands for ๐๐ณ๐ฐ๐จ๐ณ๐ข๐ฎ ๐๐ท๐ข๐ญ๐ถ๐ข๐ต๐ช๐ฐ๐ฏ ๐ข๐ฏ๐ฅ ๐๐ฆ๐ท๐ช๐ฆ๐ธ ๐๐ฆ๐ค๐ฉ๐ฏ๐ช๐ฒ๐ถ๐ฆ. Even though it was first used by the US Navy in the 50โs for the development of the Polaris submarine-launched nuclear missile, itโs not rocket science:
In PERT, for each project task we calculate 3 durations:
๐ Optimistic (O): min. time to accomplish (best-case scenario)
๐ Pessimistic (P): max. time to accomplish (worse-case scenario)
๐ Most Likely (M): best current estimate to accomplish
A project plan for each of the three scenarios can then be developed and analyzed in MS Project, Excel, etc. to determine a RANGE of project durations and completion dates.
๐๐๐๐๐ ๐๐๐ ๐จ๐ ๐๐๐๐ ๐ข๐ง๐๐ฅ๐ฎ๐๐:
โ A series of realistic scenarios for our project based on what can go right AND what can go WRONG!
โ NOT being tied down to a single (uncertain) date, since the output is a RANGE of completion times.
โ An estimate of the VARIABILITY in our project timeline.
Even IF a completion date cannot be moved (say due to an audit or regulatory deadline), the three estimates can be used to calculate project duration with:
๐น Additional resources (Optimistic)
๐น Current resources (Most Likely)
๐น Less resources (Pessimistic)
Which can help us figure out whether weโll need additional people, machines, material, etc. to meet our deadline.
We would not make an important decision based on a sample of n = 1 if we could avoid it, so why base your project timeline on a single estimate?
Give PERT analysis a try when scheduling your next project.